1. Field of the Invention
The present invention relates to a molded product in which a coating or the like is applied on a surface of a skin portion or the like of a steering wheel, parting surface covering masks for using to mold the product, and producing methods of these.
2. Description of the Related Art
A steering wheel of a vehicle generally includes a core metal, which is composed of a ring-shaped rim, a boss that is provided at the center of the rim and is disposed at a position in an axial direction of the rim, and spokes that integrally connect the rim and the boss. Further, resin molding using a synthetic resin material such as a urethane resin is provided in the core metal around portions of the rim and around spokes.
The resin molding for the core metal uses a kind of insert molding. Namely, the resin molding is provided at predetermined portions of the core metal, e.g., the rim, by mounting the core metal to a mold corresponding to portions of the core metal at which the resin molding is provided, and by filling a molten synthetic resin material into the mold after the core metal has been mounted to the mold.
At present, a coating mainly intended to improve weather-resistance and wear-resistance is applied on surfaces of the resin molding portions of the steering wheel. The coating is generally formed on the surfaces of the resin molded portions after the resin molding has been completed, by applying a coating agent to an internal peripheral surface of a cavity of the mold by a spray gun or the like when the resin molding is conducted.
Since the coating agent is sprayed on the mold by the spray gun or the like as described above, the coating agent is applied not only to the cavity but also to a parting line (parting surfaces of the mold). The coating agent applied to the parting line remains as flash such as a flange at the steering wheel after the molding has been completed. Therefore, a cutting operation for the flash has been required. This causes a problem of increased operation processes, and thus, increased cost.
In view of the above facts, an object of the present invention is to obtain a molded product which is free of the flash resulting from application of the coating agent or the like, parting surface covering masks for preventing the flash, and producing methods of the molded product and the parting surface covering masks.
A first aspect of the present invention is a molded product comprising: a molded body, which is formed by filling a molding material into molds composed of a plurality of molding member components, with molding portions being formed at some of the molding member components; and a coating, which is formed on surfaces of the molded body by a predetermined coating agent; wherein the coating is formed by mounting masks to coated-portion molding members of some of the plural molding member components before the molding material is filled, the coated-portion molding members corresponding to portions of the molded body to which the coating is applied, the masks being capable of covering parting surfaces of the coated-portion molding members and being formed by using the mold-shapes of the coated-portion molding members; applying the coating agent to the molding portions of the coated-portion molding members in the state in which the masks have been mounted; and removing the masks from the coated-portion molding members after the coating agent has been applied, clamping the molds together, and molding the molded body.
In the molded product having the above structure, the coating is applied on at least a portion of the surface of the molded body which is formed of the molding material. The coating is formed; by applying the coating agent to the molding portions of the coated-portion molding members, which correspond to the portions of the molded body to which the coating is applied, of a plurality of molding member components such as core molds, cavity molds and plate molds, which compose the mold used to mold the molded body, and by filling the molding material into the mold in the state in which the coating agent has been applied.
When the coating agent is applied to the molding portions of the coated-portion molding members in order to mold the molded product, the masks formed by using shapes of the coated-portion molding members are mounted onto the parting surfaces of the coated-portion molding members so as to cover the parting surfaces. Therefore, when the coating agent is applied in the state in which the parting surfaces have been covered with the masks, the coating agent is applied to the molding portions and the masks, but not to the parting surfaces covered with the masks. In other words, the coating agent which would be applied to the parting surfaces if the masks were not mounted is applied to the masks when the masks are mounted. Accordingly, when the masks are removed from the coated-portion molding members, the coating agent remains essentially only at the molding portions of the coated-portion molding members. Further, when the molding material is filled into the mold in the state in which the coating agent has been applied only to the molding portions, so as to mold the molded body, the coating is applied onto the surface of the molded body.
As described above, according to the present invention, the coating agent is not applied to the parting surfaces, because the coating agent which would be applied to the parting surfaces if the masks were not mounted is applied to the masks. Therefore, after the molding has been completed, the coating agent does not remain as flash or the like, which would result from application of the coating agent to the parting surfaces. Accordingly, a removing operation for the flash formed of the coating agent can be eliminated, and thus, producing processes can be considerably reduced.
In the present invention, the coating (and the coating agent) merely needs to be formed as a film or as a layer/layers on the surface of the molded body, and does not need limited functions and effects. The coating may be intended to provide various functions and effects, for example, weather-resistance, wear-resistance, antibacterial properties and reinforcement. Further, the coating (and the coating agent) may be intended to provide color paint, and colorless paint so-called clear paint for glaze or the like, or to decorate the molded body.
In the present invention, the molding material for forming the molded body does not need limited properties or forms (liquid, solid, powder or the like), and the molding material may be a synthetic resin material used for resin molding or a metal powder used for powder metallurgy molding or the like.
A second aspect of the present invention is a method for producing a molded product, wherein a coating comprising a predetermined coating agent is applied on a surface of a molded body formed by filling a molding material into a mold, the method comprising the steps of: a) mounting masks onto parting surfaces of coated-portion molding members of some of plural molding member components which compose the mold, with molding portions that mold the molded body being formed at some of the molding member components, the coated-portion molding members corresponding to portions of the molded body to which the coating is applied, the masks being capable of covering the parting surfaces of the coated-portion molding members and being formed by using the mold-shape of the mold of the coated-portion molding members; b) applying the coating agent to the molding portions of the coated-portion molding members in the state in which the masks have been mounted; c) removing the masks from the coated-portion molding members after the coating agent has been applied; and d) filling the molding material into the mold.
In the producing method of the molded product having the above structure, in the mask mounting process prior to the molding material filling process, the masks formed by using shapes of the coated-portion molding members are mounted to the coated-portion molding members which molds the portions of the molded body to which the coating is applied, so as to cover the parting surfaces of the coated-portion molding members.
Then, in the applying process, the coating agent is applied to the molding portions of the coated-portion molding members. At this time, for example, if the coating agent is applied by a spray gun or the like in consideration of application efficiency (e.g., operation efficiency and uniformity of application), the coating agent is applied not only to the molding portions but also to surrounding vicinities thereof. However, since the parting surfaces of the coated-portion molding members have been covered with the masks, the coating agent which would be applied to the parting surfaces of the coated-portion molding members is essentially applied to the masks, and the coating agent is not applied to the parting surfaces of the coated-portion molding members.
Further, in the mask removing process after the applying process, the masks are removed from the coated-portion molding members.
After that, the molding material is filled into the mold so as to mold the molded body. At this time, since the coating agent has been applied to the molding portions of the coated-portion molding members, the coating agent adheres to the surface of the molded body molded in the mold, such that the coating is formed on the surface of the molded body.
In the producing method of the molded product, the coating agent, which would be applied to the parting surfaces of the coated-portion molding members if the mask mounting process in which the masks are mounted to the coated-portion molding members, is applied to the masks by mounting the masks are mounted to the parting surfaces of the coated-portion molding members. Thus, even when the masks are removed in the mask removing process after the applying process, the coating agent has not been applied to the parting surfaces of the coated-portion molding members. Therefore, after the molding has been completed, the coating agent does not remain as flash or the like, which results from application of the coating agent to the parting surfaces. Accordingly, a removing operation for the flash formed of the coating agent can be eliminated, and thus, producing processes can be considerably reduced.
In the present invention, the coating (and the coating agent) merely needs to be formed like a film or a layer/layers on the surface of the molded body, and does not need limited functions and effects. The coating may be intended to provide various functions and effects, for example, weather-resistance, wear-resistance, antibacterial property and reinforcement. Further, the coating (and the coating agent) may be intended to provide color paint, and colorless paint so-called clear paint for glaze or the like, or to decorate the molded body.
In the present invention, the molding material for forming the molded body does not need limited properties or forms (liquid, solid, powder or the like), and the molding material may be a synthetic resin material used for resin molding or a metal powder used for powder metallurgy molding or the like.
A third aspect of the present invention is a mask for covering parting surfaces, the mask being mountable to coated-portion molding members corresponding to portions of a molded body surface on which a coating is formed, before a molding material which forms the molded body is filled into a mold composed of a plurality of molding member components, with molding portions being formed at some of the molding member components, the mask having a shape that corresponds to the surface shape of the coated-portion molding member, wherein the mask is formed by using the coated-portion molding member, and covers parting surfaces of the coated-portion molding member in the state in which the mask is mounted to the coated-portion molding member.
The parting surface covering masks having the above structure are formed by using shapes of the coated-portion molding members, so that the masks can be mounted to the coated-portion molding members corresponding to portions of the molded body on which the coating is applied.
When the parting surface covering masks are mounted to the coated-portion molding members before the molding material is filled into the mold, the parting surfaces of the coated-portion molding members are covered with the parting surface covering masks. In this state, when the coating agent forming the coating is applied to the coated-portion molding members by a spray gun or the like, the coating agent adheres to the molding portions of the coated-portion molding members, and to the surrounding vicinities of the molding portions, i.e., the parting surface covering masks.
When the parting surface covering masks are removed from the coated-portion molding members after the coating agent has been applied, the coating agent essentially remains only at the molding portions of the coated-portion molding members, and the coating agent does not remain at the parting surfaces. After that, when the coated-portion molding members are clamped together in the state in which the parting surface covering masks have been removed from the coated-portion molding members, and the molding material is filled into the mold so as to mold the molded body, the coating is applied only to portions of the surface of the molded body corresponding to the molding portions of the coated-portion molding members.
Since the coating agent does not adhere to the parting surfaces by mounting the parting surface covering masks to the coated-portion molding members when the coating agent is applied as described above, flash, which results from molding the molded body after the coating agent has been applied to the parting surfaces, are not formed at the molded body. Accordingly, a removing operation for the flash formed of the coating agent used for molding can be eliminated, and thus, producing processes can be considerably reduced.
Preferably, the mask for covering parting surfaces of the present invention further comprise: mask bodies, whose peripheries correspond to peripheries of the parting surfaces and whose portions facing the parting surfaces are formed in correspondence with the parting surfaces; and adjusting portions, which are fixed to at least the peripheries or the facing portions of the mask bodies, and whose portions fixed to the mask bodies are formed in correspondence with shapes of the parting surfaces.
The parting surfaces covering mask having the above structure is composed of a mask body and adjusting portions. The periphery of the mask body corresponding to the peripheries of the parting surfaces and the portions thereof facing to the parting surfaces are formed in correspondence with the parting surfaces. The portions of the adjusting portions fixed to the mask body, i.e., to at least the facing portions or the periphery of the mask body, are formed in correspondence with the parting surfaces.
When there are a plurality of molding member components which mold the identical portion of the identical molded body (for example, in order to keep spare components or to produce the same type of molded body in large quantities), the shapes of the molding member components are slightly different from each other due to dimensional error or the like.
Therefore, even when the coated-portion molding members are essentially the same types, parting surface covering masks corresponding to the respective coated-portion molding members are required. Since the parting surface covering masks have a structure in which the adjusting portions are fixed to the mask bodies, if essentially the same mask bodies are used for the respective coated-portion molding members, and the adjusting portions are adjusted so as to be suitable for the respective coated-portion molding members, the mask bodies can be produced in large quantities. Accordingly, even when the parting surface covering masks are prepared for the respective coated-portion molding members, production cost for the parting surface covering masks can be reduced, and thus, the entire production cost can be also reduced.
Also, if the essential shapes of the coated-portion molding members are identical or similar to each other for other applications or other types of molding, the production cost for the parting surface covering masks can be reduced, because the same mask bodies can be used.
Further, in the present invention, the periphery of the mask body may correspond to external peripheries of the parting surfaces, or to internal peripheries thereof.
Preferably, in the mask for covering parting surfaces of the present invention, the adjusting portions are formed by time-hardening members harden after an elapse of predetermined period of time, wherein the time-hardening members can tightly contact the mask bodies, can be plastically deformed and partially cut off by an external force applied thereof, and are integrally bonded to the mask bodies by hardening while adhering to the mask bodies.
In the parting surfaces covering mask having the above structure, the adjusting portions are formed by the time-hardening members. Namely, when the adjusting portions are formed, the mask body is set on the parting surfaces of the coated-portion molding member in the state in which the time-hardening members are attached at the predetermined positions on the mask body, and the time-hardening members are plastically deformed by adding an external force in the state in which the mask body is set, so as to correspond to the parting surfaces.
Then, unnecessary time-hardening members are cut off before or after time-hardening members are hardened, and thereby the parting surfaces covering mask corresponding to the coated-portion molding member on which the mask has been set is formed. When the adjusting portions are formed of the time-hardening members in this manner, the parting surface covering masks corresponding to the respective coated-portion molding members can be formed with considerable ease. Accordingly, the production cost for the parting surface covering masks can be further reduced, and thus, the entire production cost can be also further reduced.
In the present invention, cure time of the time-hardening member is not particularly limited. Essentially, a time-hardening member having a relative short cure time or that having a relative long cure time may be used. When the time-hardening member having a short cure time is used, time for producing the parting surface covering masks can be reduced, and thus, the parting surface covering masks can be rapidly used. On the other hand, when the time-hardening member having a long cure time is used, even if a long operation time is required by a unskilled operator, the parting surface covering masks can be reliably made to correspond to the coated-portion molding members.
Preferably, the mask for covering the parting surfaces of the present invention further comprise engaging portions, which engage with predetermined portions of the coated-portion molding members in the state in which the masks being mounted to the coated-portion molding members such that the masks are held by the coated-portion molding members.
In the parting surfaces covering mask having the above structure, when the parting surfaces covering mask is mounted to the coated-portion molding member, the engaging portions provided at the parting surfaces covering mask engage with predetermined portions of the coated-portion molding member, such that the parting surfaces covering mask is held by the coated-portion molding member. Accordingly, the parting surfaces covering mask is easily positioned at the coated-portion molding member, and thus, operation efficiency is improved.
A fourth aspect of the present invention is a method for producing masks for covering parting surfaces, the masks being mountable to coated-portion molding members, the coated-portion molding members being members of plural molding member components which compose a mold for molding a molded product having a surface coated, and which include molding portions for molding the coated portions of a molded body, the masks covering parting surfaces of the coated-portion molding members in the state in which the masks are mounted to the coated-portion molding members, the masks preventing a coating agent applied to the molding portions from adhering to the parting surfaces before the coated-portion molding members are clamped together; the method comprising the steps of: a) molding mother-molds corresponding to the parting surfaces, by laminating a mother-mold molding member, which reaches a predetermined rigidity after hardening, to the parting surfaces of the coated-portion molding members, and to predetermined portions of the coated-portion molding members except the molding portions to which the coating agent is applied, and molding the mother-mold molding member along the parting surfaces and the predetermined portions of the coated-portion molding members; b) producing mask-forming molds including mask-forming portions whose peripheries correspond to peripheries of the mother-molds by tightly attaching a mold-forming member to substantially all peripheries of the mother-molds; and c) molding at least mask bodies of the masks covering the parting surfaces by filling a mask-molding material into the mask-forming molds.
In the producing method of the parting surface covering masks having the above structure, initially, in the mother-mold molding process, a mother-mold molding member is laminated to the parting surfaces of the coated-portion molding members including the molding portions for molding portions of the molded body to which the coating is applied, and to predetermined portions of the molding portions except the portions on which the coating agent is applied, and the mother-mold molding member is molded along the parting surfaces of the coated-portion molding members and the predetermined portions thereof except the molding portions to which the coating agent is applied. When the molded mother-mold molding member has been hardened, the mother-molds (masters) are formed.
Then, in the mold producing process, the mask-forming molds are produced. In this process, the mold forming member which forms the mask-forming molds is attached to the substantially entire peripheries of the mother-molds. Further, when the mold forming member which has been attached to the mother-molds (i.e., the mask-forming molds before the mother-molds are removed) is split to remove the mother-molds, the mask-forming portions whose internal peripheries correspond to the external peripheries of the mother-molds are formed at the portions in which the mother-molds have been accommodated.
In the next mask molding process, the mask molding material is filled into the mask-forming molds, i.e., to the mask-forming portions. As a result, at least mask bodies of the parting surface covering masks are molded.
In this manner, in the producing method of the parting surface covering masks, the mother-molds are molded by using the coated-portion molding members which mold the molded product, and further, the mask-forming molds are formed using the mother-molds. Therefore, the outer shapes of the parting surface covering masks can be formed with considerable ease so as to be identical or very similar to the shapes of the parting surfaces of the coated-portion molding members, and thus, the production cost for the parting surface covering masks can be reduced. Further, since the parting surface covering masks can be easily produced in large quantities by using the mask-forming molds repeatedly, unit cost for producing the parting surfaces covering mask can be reduced.
The production cost for the parting surface covering masks affects the production cost for the molded product. Thus, when the parting surface covering masks are produced by using the producing method of the present invention, the production cost for the molded product can be reduced.
In the present invention, the peripheries of the mother-molds may be external peripheries or internal peripheries thereof.
Preferably, in the producing method of the parting surface covering masks of the present invention, a mold-filling member, which is plastically deformed by a predetermined amount or more of external force, is laminated to vicinities of the parting surfaces of the coated-portion molding members such that the vicinities of the parting surfaces are formed in predetermined shapes, before the mother-molds are molded.
In the producing method of the parting surface covering masks having the above structure, the mold-filling member laminating process is conducted prior to the mother-mold molding process. In the mold-filling member laminating process, the mold-filling member, which is plastically deformed by a predetermined amount or more of external force, is laminated to the vicinities of the parting surfaces of the coated-portion molding members, such that the mold-filling member is formed in predetermined shapes.
As a result, at the portions of the coated-portion molding members to which the mold-filling member has been laminated, irregularity of the molding portions of the coated-portion molding members is covered with the mold-filling member, such that the coated-portion molding members have relatively simple shapes. Since the purpose of the parting surface covering masks is to cover the parting surfaces so that the coating agent is not applied to the parting surfaces, as long as the parting surface covering masks attain the purpose, the shapes thereof are not limited. Thus, the parting surface covering masks merely need irregularity corresponding to the molding portions formed at the coated-portion molding members, so as to cover the parting surfaces.
In the producing method of the present invention, as described above, at the portions of the coated-portion molding members to which the mold-filling member has been laminated, irregularity, which is unnecessary for the parting surface covering masks, of the molding portions of the coated-portion molding members to which the coating agent is not applied, is covered with the mold-filling member. Therefore, the coated-portion molding members will have simple shapes. When the mother-mold molding member is laminated to the parting surfaces of the coated-portion molding members and to the laminated mold-filling member, unnecessary irregularity is not formed in the mother-molds.
Therefore, unnecessary irregularity is not formed in the mask-forming molds which are formed based on the mother-molds, and further, unnecessary irregularity is not formed in the parting surface covering masks which are formed based on the mask-forming molds. Accordingly, the mother-mold molding member and the mask molding material can be saved, and thus, the production cost can be reduced and the parting surface covering masks can be lightened.
Preferably, the producing method of the parting surface covering masks of the present invention further comprises the steps of: attaching adjusting members, which are plastically deformed by at least a predetermined amount of external force, to at least one of peripheries of the mask bodies and portions of the mask bodies facing the parting surfaces; and forming the adjusting members in correspondence with shapes of surfaces of the coated-portion molding members by pressing the mask bodies toward the coated-portion molding members in a state in which the mask bodies to which the adjusting members being attached are temporarily mounted to the coated-portion molding members.
In the producing method of the parting surface covering masks having the above structure, in the adjusting members attaching process, the adjusting members are integrally attached to at least the peripheries of the mask bodies or the portions of the mask bodies facing to the parting surfaces, which have been molded through the mask molding process. Then, in the adjusting member forming process, the mask bodies to which the adjusting members have been attached are temporarily mounted to the coated-portion molding members, and the mask bodies are pressed toward the coated-portion molding members.
The adjusting members are plastically deformed by a predetermined amount or more of external force. Therefore, when the mask bodies are pressed toward the coated-portion molding members, due to pressing force from the mask bodies and reactive force from the coated-portion molding members, the adjusting members which have been attached to the mask bodies are plastically deformed so as to have shapes corresponding to the surfaces of the coated-portion molding members. Since the adjusting members have been plastically deformed so as to have shapes corresponding to the surfaces of the coated-portion molding members in this manner, the parting surface covering masks are mounted to the coated-portion molding members without gaps therebetween.
Accordingly, even when the coating agent is applied to the coated-portion molding members by a spray gun or the like, the coating agent will not enter between the parting surface covering masks and the coated-portion molding members.